Monolithic composite wing manufacturing process

• US 6,190,484 B1
• Filed: 02/19/1999
• Issued: 02/20/2001
• Est. Priority Date: 02/19/1999
• Status: Expired due to Fees

• Current Assignee: Kari Appa
• Original Assignee: Kari Appa
• Inventors: Appa, Kari
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): WARD, JESSICA LEE
• Application Number:
  US09/252,750
• Time in Patent Office: 732 Days
• Field of Search: 156/166, 156/169, 156/172, 156/173, 156/182, 156/184, 156/185, 156/189, 156/195, 156/242, 156/245, 156/425, 244/123
• US Class Current: 156/189
• CPC Class Codes: B29C 70/32 on a rotating mould, former or core
• CPC Class Codes: B29C 70/342 using isostatic pressure
• CPC Class Codes: B29C 70/386 Automated tape laying [ATL]
• CPC Class Codes: B29L 2031/3085 Wings
• CPC Class Codes: B64C 3/20 Integral or sandwich constructions
• CPC Class Codes: B64F 5/10 Manufacturing or assembling aircraft, e.g. jigs therefor
• CPC Class Codes: Y02T 50/40 Weight reduction

Abstract

A method of manufacturing a monolithic composite wing without using mechanical fasteners is described. The process begins with the formation of a center wing box in combination with a pair of spars, riblets and a pair of skin-molds including the wrapping and binding of the box by means of resin impregnated composite tapes. Next, additional cells are adjoined contiguously on either side of the current framework and an overlap wrapping and bonding process is continued around the current framework. The overlap wrapping and binding procedure provides increased torsion stiffness and reduced structural weight. All cells up to the leading and trailing edges will be included in the assembly process. Conduits to convey fuel, hydraulic fluid and electrical wiring will also be installed in designated cells. Finally, the completed wing will be cured in an autoclave under uniform pressure and temperature.

Claims

1. A method of manufacturing a monolithic composite wing comprising the steps of:

(a) fabricating a center wing box cell having a pair of longitudinally disposed U-shaped pre-formed spars, laterally disposed plurality of rib-lets between said spars, and a pair of resin impregnated wing skin-molds glued to upper and lower surfaces of said spars wherein said box cell is wrapped, compacted, and bonded by means of locally heated resin impregnated composite tapes in a plurality of layers along spanwise and helical directions; and

(b) adjoining additional boxes contiguously disposed in the lateral direction on either side to form a framework, wherein wrapping, compacting, and bonding of said additional boxes includes overlapping the previously wrapped boxes in said framework by means of said locally heated resin impregnated composite tapes in a plurality of layers along spanwise and helical directions; and

(c) repeating said fabrication procedure described in said step (b) until all boxes up to and including the leading edge and the trailing edge box cells of said wing are added;

including

(d) installing conduit devices for fuel, hydraulic systems and electrical services;

(e) spraying the inner surface of the wing box with fuel leak proof chemical compounds;

(f) providing inspection cutouts and placing reinforcement tapes around said inspection cutouts; and

(g) curing said wing in an autoclave under controlled uniform pressure and temperature.

2. A method according to claim 1 in which contoured wing skin-molds are made of honeycomb sheets or a plurality of woven composite fabrics having integrally bonded hat shaped stiffeners disposed in longitudinal and lateral directions.

3. A method according to claim 1 in which an advanced tow placement device traveling along an elliptic shaped track places dual or multiple tapes simultaneously around the wing being able to traverse from the wing root to wing tip.